阅读说明：本技术 一种熔体萃取分离回收废旧镍基高温合金中镍钴的方法 (Method for recovering nickel and cobalt in waste nickel-based high-temperature alloy through melt extraction separation ) 是由 田庆华 甘向栋 郭学益 崔富晖 于大伟 张纯熹 于 2020-01-06 设计创作，主要内容包括：本发明公开了一种熔体萃取分离回收废旧镍基高温合金中镍钴的方法,包括下述的步骤：S1.以熔融Mg-M合金为萃取介质,以废旧镍基高温合金为待萃取物,进行萃取处理,得到共熔体与合金残渣,在所述Mg-M合金中Mg为主体金属,M金属为Pb、Bi、Sn中的一种或多种；S2.将S1得到的共熔体进行真空蒸馏,得到金属镍钴粉以及冷凝的萃取介质。本发明提出了一种清洁高效的分离回收废旧镍基高温合金中金属镍钴的方法。本方法工艺流程短,设备简单,镍钴回收率高,成本低,萃取介质可以循环利用,过程清洁环保。(The invention discloses a method for recovering nickel and cobalt in waste nickel-based high-temperature alloy by melt extraction separation, which comprises the following steps: s1, extracting by taking molten Mg-M alloy as an extraction medium and waste nickel-based high-temperature alloy as an extract to be extracted to obtain a eutectic and alloy residues, wherein Mg in the Mg-M alloy is a main metal, and M is one or more of Pb, Bi and Sn; and S2, carrying out vacuum distillation on the eutectic obtained in the step S1 to obtain metal nickel cobalt powder and a condensed extraction medium. The invention provides a method for cleanly and efficiently separating and recovering metal nickel and cobalt in waste nickel-based high-temperature alloy. The method has the advantages of short process flow, simple equipment, high nickel and cobalt recovery rate, low cost, recyclable extraction medium, clean and environment-friendly process.)

1. A method for recovering nickel and cobalt in waste nickel-based high-temperature alloy through melt extraction separation is characterized by comprising the following steps:

s1, extracting by taking molten Mg-M alloy as an extraction medium and waste nickel-based high-temperature alloy as an extract to be extracted to obtain a eutectic and alloy residues, wherein Mg in the Mg-M alloy is a main metal, and M is one or more of Pb, Bi and Sn;

and S2, carrying out vacuum distillation on the eutectic obtained in the step S1 to obtain metal nickel cobalt powder and a condensed extraction medium.

2. The method for separating and recovering nickel and cobalt in the waste nickel-based superalloy through melt extraction according to claim 1, wherein the mass percentage of Ni in the waste nickel-based superalloy S1 is not less than 50%, and the mass percentage of Co in the waste nickel-based superalloy is 3% -15%.

3. The method for separating and recovering nickel and cobalt in the waste nickel-based superalloy through melt extraction according to claim 1 or 2, wherein the waste nickel-based superalloy S1 is pretreated by: removing the refractory material on the surface of the waste nickel-based high-temperature alloy, and then cleaning and drying.

4. The method for separating and recovering nickel and cobalt in waste nickel-based high-temperature alloy through melt extraction as claimed in claim 1, wherein the Mg-M alloy of S1 has a Mg molar percentage content of 50-100%.

5. The method for recovering nickel and cobalt in the waste nickel-based high-temperature alloy through melt extraction and separation according to claim 1 or 4, wherein the weight ratio of the Mg-M alloy and the waste nickel-based high-temperature alloy in S1 is 3: 1-10: 1.

6. The method for recovering nickel and cobalt in waste nickel-based high-temperature alloy through melt extraction and separation according to claim 1, wherein the extraction treatment temperature of S1 is 700-1000 ℃, and the heat preservation time is 3-24 hours.

7. The method for extracting, separating and recycling nickel and cobalt in waste nickel-based high-temperature alloy through melt according to claim 1 or 6, wherein the extraction treatment S1 is that the waste nickel-based high-temperature alloy is placed in a porous and liftable titanium net, an extraction medium is placed in a crucible, then the crucible and the titanium net are placed in a well-type vacuum resistance furnace together, the temperature is raised to the extraction temperature, then the temperature is preserved, the titanium net is lifted after the temperature preservation is finished to separate two materials, a eutectic is obtained in the crucible, and alloy residues are obtained in the titanium net.

8. The method for separating and recovering nickel and cobalt in waste nickel-base superalloy by melt extraction according to claim 1 or 6, wherein the extraction process of S1 is performed in a protective gas, and the protective gas is one of argon, sulfur hexafluoride gas or helium.

9. The method for recovering nickel and cobalt in waste nickel-based high-temperature alloy through melt extraction and separation according to claim 1, wherein the vacuum distillation pressure of S2 is reduced to below 10 Pa.

10. The method for recovering nickel and cobalt in waste nickel-based high-temperature alloy through melt extraction and separation according to claim 1 or 9, wherein the vacuum distillation temperature of S2 is 700-1200 ℃, and the heat preservation time is 2-10 h.

Technical Field

The invention relates to the technical field of recovery of waste high-temperature alloys, in particular to a method for recovering metal nickel and cobalt in waste nickel-based high-temperature alloys.

Background

The nickel-based high-temperature alloy is a high-temperature alloy which takes nickel as a matrix and has stronger strength and good oxidation resistance and fuel gas corrosion resistance in the temperature range of 650-1000 ℃. The nickel-based superalloy contains a large amount of precious rare metals such as rhenium, tungsten, tantalum, niobium, hafnium and the like in addition to main metals such as nickel, cobalt, chromium and the like. The consumption of high-temperature alloy materials in the international market is nearly 30 million tons every year, so the recovery work of the high-temperature alloy has good prospect, and the high-temperature alloy which reaches the service life and the waste materials generated in the generation process are important sources for recovering the high-temperature alloy.

There are various methods for recovering valuable metal elements from high-temperature alloy scrap, such as pyrometallurgical, hydrometallurgical, and electrochemical methods. The method for recovering and preparing nickel and cobalt from the nickel-based superalloy waste mainly comprises the following steps: electrochemical dissolution treatment of chloride solution, hot acid leaching, blast acid leaching, electrochemical dissolution, pressurized acid leaching or chlorine leaching, sulfuric acid and nitric acid mixed acid chemical dissolution and the like; the recovery of waste high-temperature alloy by pyrogenic process is characterized by that it utilizes a series of techniques of surface treatment, vacuum oxygen-blowing decarbonization (VOD) and special slag system to remove impurity and high-vacuum purification, etc. and combines them with advanced smelting equipment of vacuum induction furnace and electroslag furnace to make regeneration application.

The experimental research of leaching nickel and cobalt from waste high-temperature nickel-cobalt alloy is disclosed in the No. 3 of 2009, Hou Xiaochuan, that is, nickel, cobalt and iron are leached by chlorine gas, wherein, the additive 2-valent iron improves the leaching rate, improves the utilization rate of the chlorine gas and accelerates the reaction process, the average leaching rate of nickel reaches 99.30%, and the mass fraction of nickel in the leaching slag is 0.51%.

The Chua's calculation reports the comprehensive utilization of cobalt superalloy in the ' Chinese non-ferrous metals school newspaper ', and the nickel and cobalt in the superalloy are leached by a blast leaching method. The test conditions are that the temperature is 70 ℃, the liquid-solid ratio is 10mL/g, and the blast volume is 0.9m³The blowing pressure is 300kPa, the stirring speed is 90r/min, the primary leaching rate of the nickel is 81 percent, the method reduces the consumption of acid and the consumption of materials in subsequent tests, namelyThe method is beneficial to reducing the amount of slag and the loss of nickel and cobalt, and is economical, reasonable and environment-friendly.

Fanxingxiang et al applied for a patent (application number: 201310270054.5) of preparing high-purity nickel powder from waste high-temperature alloy, melting, spraying powder, ball-milling the waste high-temperature alloy into alloy powder, then selectively leaching valuable metals such as nickel, cobalt and the like by using dilute acid to obtain a solution rich in nickel and cobalt, then extracting and separating the nickel and cobalt solution, adding alkali into the acid solution of the obtained nickel to prepare slurry, and reducing the slurry by secondary hydrogen to obtain the high-purity nickel powder, wherein the solid separator can further recover high-temperature resistant metals such as tungsten, molybdenum, rhenium, niobium, zirconium and the like, and the liquid separator can further recover cobalt, so that the whole process is green, efficient and low in cost.

The existing recovery method can only convert nickel in the high-temperature alloy waste into nickel salt or nickel powder, and has low product purity, low added value and no market competitiveness. At present, there is no report of direct conversion of nickel in superalloy returns to high purity nickel.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects and shortcomings in the background technology and providing a method for separating and recovering nickel and cobalt in waste nickel-based high-temperature alloy, which is clean and efficient and has high product purity.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

a method for recovering nickel and cobalt in waste nickel-based high-temperature alloy by melt extraction separation comprises the following steps:

s1, extracting by taking molten Mg-M alloy as an extraction medium and waste nickel-based high-temperature alloy as an extract to be extracted to obtain a eutectic and alloy residues, wherein Mg in the Mg-M alloy is a main metal, and M is one or more of Pb, Bi and Sn;

and S2, carrying out vacuum distillation on the eutectic obtained in the step S1 to obtain metal nickel cobalt powder and a condensed extraction medium.

Further, in the S1 waste nickel-based high-temperature alloy, the mass percentage of Ni is not less than 50%, and the mass percentage of Co is 3% -15%.

Further, the waste nickel-based superalloy S1 is pretreated as follows: removing the refractory material on the surface of the waste nickel-based high-temperature alloy, and then cleaning and drying.

Further, the Mg-M alloy of S1 has a Mg content of 50-100% by mol.

Further, the weight ratio of the Mg-M alloy and the waste nickel-based high-temperature alloy in the S1 is 3: 1-10: 1.

Further, the extraction treatment temperature of S1 is 700-1000 ℃, and the heat preservation time is 3-24 h.

Further, the extraction treatment in S1 is to place the waste nickel-based superalloy in a porous and liftable titanium mesh, place an extraction medium in a crucible, then place the crucible and the titanium mesh together in a well-type vacuum resistance furnace, heat up to an extraction temperature, then preserve heat, lift the titanium mesh after the preservation of heat to separate two materials, obtain a eutectic in the crucible, and obtain alloy residues in the titanium mesh.

Further, the extraction process of S1 is performed in a protective gas, where the protective gas is one of argon, sulfur hexafluoride gas, or helium.

Further, the vacuum distillation pressure of S2 is reduced to below 10 Pa.

Further, the vacuum distillation temperature of S2 is 700-1200 ℃, and the heat preservation time is 2-10 h.

The principle of the invention is as follows: the waste nickel-based high-temperature alloy is used as a raw material, Mg-M alloy is used as an extraction medium, nickel and cobalt in the waste nickel-based high-temperature alloy are selectively and efficiently extracted at a certain temperature to form a eutectic body, the eutectic body and the alloy residue exist in a solid-liquid two phase mode by utilizing the melting point difference between the eutectic body and the alloy residue and keeping the temperature to be a certain value, and the alloy residue and the eutectic body can be separated from each other by solid and liquid. The method comprises the steps of utilizing the vapor pressure difference between an extraction medium and nickel cobalt to be larger, carrying out vacuum distillation treatment on a eutectic body, and obtaining the extraction medium (Mg, M) and metal nickel cobalt powder with higher purity, wherein the nickel cobalt powder can be used as an alloy processing material, and the extraction medium can be recycled.

Experiments show that at the temperature of 1000 ℃, the mass fractions of Ni, Co and Fe in the magnesium metal melt are respectively 36 wt.%, 35 wt.% and 0.1 wt.%, the mass fractions of Ni, Co and Fe in the lead metal melt are respectively 7 wt.%, 0.1 wt.% and 0.04 wt.%, Ni, Co and Fe are basically insoluble in the bismuth metal melt, the mass fractions of Ni, Co and Fe in the tin metal melt are respectively 10 wt.%, 0.1 wt.% and 10 wt.%, and other elements in the nickel-based superalloy are basically insoluble in the Mg-M alloy melt. The Mg-M alloy has high selectivity to elements Ni and Co in the nickel-based high-temperature alloy, and the elements Fe and Cr in the high-temperature alloy hardly enter the Mg-M alloy, so that the purity of the obtained nickel-cobalt powder is high.

In addition, the melting point of Mg is 650 ℃, and after low-melting-point metal (the melting point of Pb is 327 ℃, the melting point of Bi is 271.4 ℃ and the melting point of Sn is 231.89 ℃) is added, the melting point of the Mg-M alloy is less than 650 ℃, so that the reaction temperature can be reduced, and the energy consumption can be reduced.

Compared with the prior art, the invention has the beneficial effects that:

(1) the waste nickel-based high-temperature alloy can efficiently collect nickel and cobalt from the waste nickel-based high-temperature alloy through melt extraction and vacuum distillation, the recovery rate of nickel and cobalt is high, the extraction medium can be recycled, the process flow is short, the energy consumption is low, three wastes are not generated, and the method is pollution-free, clean and environment-friendly. Effectively solves the environmental problems of long process flow, high loss rate of nickel and cobalt, waste water and waste gas generated in the process and the like of the existing wet process.

(2) The device is simple, the main device is a well type vacuum resistance furnace which is a standard part, the use is wide, the operation is simple, the manufacturing cost is lower, the specification is complete, the scale can be large or small, the investment is saved, and the popularization prospect is good.

(3) The method has low requirement on the grade of the nickel-based superalloy waste, is suitable for recycling and preparing high-purity nickel in most of the nickel-based superalloy waste, and is suitable for popularization and implementation.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a process flow diagram of the present invention for recovering metallic nickel and cobalt from waste nickel-based superalloys.

Detailed Description

In order to facilitate understanding of the invention, the invention will be described more fully and in detail with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

The method for recovering nickel and cobalt in the nickel-based superalloy by melt extraction, which is disclosed by the embodiment of the invention, comprises the following steps of:

(1) the surface of the nickel-based high-temperature alloy waste is treated to remove the refractory material on the surface of the nickel-based high-temperature alloy waste, and then the waste nickel-based high-temperature alloy is cleaned and dried to obtain a clean raw material.

The nickel-based high-temperature alloy waste comprises the main components of Ni and Co, wherein the mass percentage of Ni is not less than 50%, the mass percentage of Co is 3% -15%, and the nickel-based high-temperature alloy waste also comprises one or more than two of Cr, Fe, Mo, Ta, Al and W.

The waste nickel-based superalloy raw material can be cleaned by a nickel-based superalloy cleaning agent solution and clear water and dried to obtain a clean material.

(2) Melt extraction: and (3) taking the molten Mg-M alloy as an extraction medium and the nickel-based high-temperature alloy waste as an extract to be extracted, and extracting to obtain a eutectic (Mg-M-Co-Ni alloy) and alloy residues.

Mg in the Mg-M alloy used in the melt extraction process is used as a main metal, and preferably, the molar percentage content of Mg is in a range of 50-100%. The M metal is one or more of Pb, Bi and Sn.

Preferably, the weight ratio of the Mg-M alloy to the waste nickel-based high-temperature alloy is 3: 1-10: 1.

In one embodiment, clean nickel-based high-temperature alloy materials and Mg-M alloy are prepared according to the weight ratio of 1: 3-1: 10, the clean nickel-based high-temperature alloy is placed in a porous and liftable titanium net, an extraction medium is placed in a crucible, then the crucible and the titanium net are placed in a well-type vacuum resistance furnace together, protective gas is introduced into the furnace at the flow rate of 50-200 mL/min, a heating system is started, the temperature is increased to 700-1000 ℃, the Mg-M alloy is melted, the heat preservation time is 3-24 hours, the two materials are separated through a lifting device after the heat preservation is finished, the temperature is reduced to the room temperature after the lifting is finished, the materials are taken out, a eutectic is obtained in the crucible, and alloy residues are obtained in the porous titanium net.

Preferably, the protective gas used is one of argon, sulfur hexafluoride gas or helium.

(3) Vacuum distillation separation: and (3) carrying out vacuum distillation on the eutectic obtained in the step (2) to obtain metal nickel cobalt powder and condensed extraction media (metal Mg and M).

In a specific embodiment, the eutectic obtained in the step (2) is placed in a crucible of a well-type vacuum resistance furnace, vacuum pumping is carried out, when the pressure in the furnace is reduced to be below 10Pa, the vacuum is kept, a heating system is started, the temperature is increased to 700-1200 ℃, the temperature is kept for 2-10 h, the temperature is reduced to room temperature after the temperature is kept, materials are taken out, metal nickel cobalt powder is obtained from the crucible, and a condensed metal extraction medium is obtained from the crucible wall.

Preferably, the crucible used in steps (2) and (3) is one of a graphite crucible, an alumina crucible, a magnesia crucible, a titanium crucible, or a zirconium crucible.